Loose loops are the only way to store extension cords.
Tight coiling or wrapping around your elbow creates kinks that damage the insulation over time.
The trick is to make large, loose loops—no smaller than about a foot in diameter. Fold the cord loosely, then use the cord itself to tie it off (like a simple overhand loop) or use a Velcro strap. The “over-under” technique works well for long cords, but honestly, just don’t crush or knot it.
Keep them off concrete floors (moisture seeps into the jacket) and out of direct sunlight. A cool, dry closet or a hook on the wall is fine.
Don’t be the person who wrestles a snarled cord for ten minutes before every job. Treat them like rope, not aggressive tinsel.